Unchallenging Copenhagen Climate Challenge

Posted by Ari Jokimäki on December 10, 2009

Yet another statement signed by N number of mind-numbingly relevant people is being spammed onto climate related blogs and discussions. This one is called Copenhagen Climate Challenge. Here, I will just comment on some of the things in their statement:

Therefore, there is no sound reason to impose expensive and restrictive public policy decisions on the peoples of the Earth without first providing convincing evidence that human activities are causing dangerous climate change beyond that resulting from natural causes.

So you don’t think that the potential risk of worldwide catastrophe to both mankind and the global ecosystem as a whole is not “sound reason”? Do you take fire insurance only after your house has burned down?

Before any precipitate action is taken, we must have solid observational data demonstrating that recent changes in climate differ substantially from changes observed in the past…

Past has nothing to do with it. All we need to know is that it has created a very risky situation now.

We the undersigned, being qualified in climate-related scientific disciplines, challenge the UNFCCC and supporters of the United Nations Climate Change Conference to produce convincing OBSERVATIONAL EVIDENCE for their claims of dangerous human-caused global warming and other changes in climate. Projections of possible future scenarios from unproven computer models of climate are not acceptable substitutes for real world data obtained through unbiased and rigorous scientific investigation.

If you look down the list sorted by number of works indexed in Google Scholar that mention climate, the “skeptics” median output by this count is 2. The median for the IPCC is 93. Qualified experts indeed.

Ari Jokimäkisaid

Hey, I think I have seen your site before. At one point I started assembling a list of scientists who have authored papers where it is explicitly said that mankind is changing the climate. That’s on hold now (with some 100+ names I think), but I probably browsed your site back then also.

Edited to add: Hmm… I think your list of 2900 climate authors could be used to further determine which ones of them have actually been authoring a paper that says mankind is changing climate. I’m interested in that angle because that is the most honest way to see their scientific opinion on the matter.

If you look down the list sorted by number of works indexed in Google Scholar that mention climate, the “skeptics” median output by this count is 2. The median for the IPCC is 93. Qualified experts indeed.

Ahh, but that’s probably because they so often confuse weather with climate. I’m sure they would rank well if you would use “weather” instead of “climate”.😉

– Everyone who has studied the subject knows that currently our biggest source of uncertainty is the climate feedbacks, but even there we have direct observations of positive water vapor feedback and the latest research on low-level clouds (where the biggest uncertainty has been) also shows positive feedback.

You are conveniently omitting the longest term record, the RAOB data, which
indicates a NEGATIVE feedback

As the papers on your site also observe,
there are contradictory analyses of cloud cover, making pronouncements of
cloud feedback tenuous at best.

– Just about all major things are working as expected in greenhouse gas warmed world. For example, stratosphere has been observed cooling, as expected. The scientific research also shows that greenhouse gases have been major factor in past climate changes.

Except:
* the warming trends are all below the best IPCC estimate for even the ‘low’ scenario, cited above.
* The stratosphere warmed for the decade prior to El Chichon, warmed between El Chichon’s resolution and Pinatubo, and while the mid to upper stratosphere has cooled since
Pintubo’s resolution, the lower stratosphere is nearly unchanged.RATPAC StratUAH MSU StratRSS MSU Strat
* the above data also indicate no such tropical upper tropospheric ‘hot spot’ occurred.
* the raob data cited above indicate drying aloft

– Other forcings are not present strongly enough. It is not the Sun, the clouds, or the cosmic rays.

We can say that qualitatively solar increase would account for
a warming trend through the twentieth century and a maximum in the late twentieth century:http://aom.giss.nasa.gov/srsun.html

This sets up a clear experiment going forward, given the ongoing solar slowdown:
(Solar Slowdown)

Solar theory predicts a cooling trend.
CO2 theory predicts a warming trend.
We can observe going forward which is correct.

…

Antesaid

The estimated low end 1.8 °C is for the entire century – it says nothing about the short term trends.
So what do they say about the short term? You cited it yourself.“# A temperature rise of about 0.1 °C per decade would be expected for the next two decades, even if greenhouse gas and aerosol concentrations were kept at year 2000 levels.
A temperature rise of about 0.2 °C per decade is projected for the next two decades for all SRES scenarios.”

Now, to get a real trend of the temperature rise, let’s use the current 30-year trendline. (see tamino for a discussion on the timeframe needed)
So what do GISTEMP give us if we do a trendline for the last 30 years?
Answer: 0.18 °C / decade. That’s pretty much “about 0.2 °C” if you ask me.

Since Jan 2001, ALL of the above data sets
indicate a cooling trend with the exception of GISS.

This trend will vary going forward of course.
We will all be the scientists observing these numbers,
but isn’t it ironic that just as soon as the IPCC
actually put some predictions out with the fourth assessment
confidently predicting 0.2C per decade,
with a floor of 0.1C even if CO2 ceased accumulating,
that the cooling actually started?

Ari Jokimäkisaid

Edited to add: sorry I didn’t reply sooner, I was travelling for few days and then this sort of drifted to the background for a while.

Even the widely smoothed GISS falls short of the best estimate for low end rate of 1.8 °C.

Where is the research paper that shows that the expected temperature evolution does not match the observations. It is not simply taking a number from a scenario’s end result and then drawing a line from zero to that number, plotting the observed temperature trends on that and expecting that every measured value has to be on that line. It needs to be understood that some feedbacks are slow starters, so the expectation is not simple linear trend, but one that accelerates.

It also seems to me that Easterling & Wehner (2009) might be something for you to read (you can see also the expected accelerating trend in their figure 2).

You are conveniently omitting the longest term record, the RAOB data, which indicates a NEGATIVE feedback

I wonder why is it that the people who come in arguing against AGW so often immediately start throwing around these dishonesty accusations?

No matter what the subject is, you can always find one or two papers that show different results than the vast majority of the research. In your reference, the authors are themselves warning about the radiosonde data: “It is accepted that radiosonde-derived humidity data must be treated with great caution, particularly at altitudes above the 500 hPa pressure level.” It seems to me that this paper presents a curiosity at best. They use data that most agree is not very well suitable to what they are doing with it, and they find a strange result in light of other research in the field, so it remains to be seen if there’s something that arises from this to make the radiosonde measurements better. Beyond that, I don’t think there’s anything in this paper that would shake our knowledge of atmospheric physics.

As the papers on your site also observe, there are contradictory analyses of cloud cover, making pronouncements of cloud feedback tenuous at best.

Thank you for making this comment; it made me notice that I had wrong link relating to the cloud feedbacks in tha above texts. I have now inserted the correct link.

It is common knowledge that low-level cloud feedback has been a problem. I noted that latest research about it indicates positive feedback (it would have been nice to have correct link there though). I specifically meant Clement et al. (2009). Sorry for the confusion.

The stratosphere warmed for the decade prior to El Chichon, warmed between El Chichon’s resolution and Pinatubo, and while the mid to upper stratosphere has cooled since Pintubo’s resolution, the lower stratosphere is nearly unchanged.

And yet, the big picture on stratosphere shows it cooling as expected. If you want to pick on these minor details, you have to remember that there are many factors that influence stratospheric temperatures and you need to find out which ones were at work on your details before you can claim that things are not working there as expected.

the above data also indicate no such tropical upper tropospheric ‘hot spot’ occurred.

Jack Marinsaid

Where is the research paper that shows that the expected temperature evolution does not match the observations. It is not simply taking a number from a scenario’s end result and then drawing a line from zero to that number, plotting the observed temperature trends on that and expecting that every measured value has to be on that line. It needs to be understood that some feedbacks are slow starters, so the expectation is not simple linear trend, but one that accelerates.

Well, complete century predictions are not really verifiable in a human lifetime.

Fortunately, the IPCC makes a prediction for us to analyze when they say:

Of course, they weren’t explicit with WHICH two decades, but that clearly hasn’t happened
over the most recent one, two or three decades.

No matter what the subject is, you can always find one or two papers that show different results than the vast majority of the research. In your reference, the authors are themselves warning about the radiosonde data: “It is accepted that radiosonde-derived humidity data must be treated with great caution, particularly at altitudes above the 500 hPa pressure level.” It seems to me that this paper presents a curiosity at best. They use data that most agree is not very well suitable to what they are doing with it, and they find a strange result in light of other research in the field, so it remains to be seen if there’s something that arises from this to make the radiosonde measurements better. Beyond that, I don’t think there’s anything in this paper that would shake our knowledge of atmospheric physics.

Yes, there are lots of problems measuring humidity (which includes satellite measurements)
None the less, the only available long term data set of humidity indicates not only
does a modeled positive feedback fail to occur but actually a negative feedback is observed.

It is pretty much safe to say currently that the “hot spot” is there as expected. There still might be some slight tuning needed for models and observations, but it’s there.

The above link is from, as the url suggests, the NASA GISS model.
The solar data suggests that insolation increased through the
twentieth century and reached a peak in the late twentieth century.
If one knew nothing else about any other forcing or circulation changes,
one would not be surprised that temperatures warmed to a centuries
long maximum over the course of the twentieth century.